In mounting elongate structures on rooftops, for instance elongate structures such as piping for plumbing, heating, ventilating, and air conditioning, several design considerations are involved, including weight of the elongate structures, and expansion and contraction of the elongate structures. Mounting systems which do not provide a secure attachment or which are not able to support the weight of heavy elongate structures, will damage the roof, and potentially cause leakage and damage to an interior of the building.
Other design considerations for mounting systems include the materials used for the mounting system. Some mounting systems are not durable are more susceptible to deterioration than others, and can only be used in mild climates. For example, snow and rain can deteriorate some mounting structures. Unprotected metal structures may rust and wood mounting structures may rot. In locations where extreme heat or humidity are common, the mounting structures may also deteriorate due to high heat, or wide changes in heat. Once the mounting structure becomes damaged, it is likely to fail to provide adequate support to an elongate structure resulting in damage to the roof.
One attempt at mounting pipes to rooftops has been to use wood mounting blocks located at spaced intervals along the pipe. The pipe is secured to the mounting block and then the entire assembly rests upon the roof. One drawback of the wood mounting bocks is that expansion and contraction of the pipes results in translation of the mounting blocks over the surface of the roof, which is likely to damage the roof. Another disadvantage is that wood mounting structures tend to rot and disintegrate, adding further possibility of damaging the roof. Additionally, different sized wood blocks may be needed for mounting on slightly irregular surfaces, so that the weight of the pipes is distributed to each wood block. Furthermore, the wood blocks are relatively heavy, resulting in difficulties in transporting a large number of them collectively, i.e. on a pallet, up to the roof.
Another attempt at a pipe supporting device is described in U.S. Pat. No. 4,502,653 by Marvin R. Curtis, Jr. This structure has a flat bottom and an upwardly tapered structure with a pocket for positioning a pipe and roller positioned in a receiving trough. As the pipe expands or contracts, it rides on the roller which rotates within the trough, however, this structure does not provide a means to secure the pipe, nor does it provide for lateral motion of the pipe.
Another attempt at mounting pipes is called a QUICK “PIPE” BLOCK by Nelson-Olsen, Inc of Plymouth, Minn. The QUICK “PIPE” BLOCK is a 12″×6″×3.5″ high density polyethylene block which rides on a ¾″ STYROFOAM pad. A pipe is laid on the rigid block and a metal strap laid over the pipe is attached at each end by inserting fasteners into the rigid block. One disadvantage is that the block uses predrilled holes to receive the fasteners. If the predrilled holes do not provide adequate pipe placement the rigid block must either be drilled again or not used at all, frustrating rapid installation of piping. If the block detaches from the STYROFOAM pad, or the STYROFOAM pad deteriorates, the block may damage a roof due to repeated expansion and contraction of the piping. Another disadvantage is that different sized blocks may be needed for mounting on slightly irregular surfaces, so that the weight of the pipes is distributed to each block. This further frustrates rapid installation of piping. Another disadvantage of this system is that the holes in the rigid block limit the number and type of pipe fasteners which may be used, and the number of pipes which may be mounted to a single block are limited thereby.
Accordingly, there is a need for a mounting system which permits motion of mounted structures, and which permits mounting of relatively heavy mounted structures. What is also needed is a mounting system which protects the mounting surface from damage.